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From:   Jim Quinlan <james.quinlan@broadcom.com>
To:     james.quinlan@broadcom.com,
        Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Cc:     Jim Quinlan <james.quinlan@broadcom.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Rob Herring <robh@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        bcm-kernel-feedback-list@broadcom.com (maintainer:BROADCOM BCM7XXX ARM
        ARCHITECTURE),
        linux-rpi-kernel@lists.infradead.org (moderated list:BROADCOM
        BCM2711/BCM2835 ARM ARCHITECTURE),
        linux-arm-kernel@lists.infradead.org (moderated list:BROADCOM
        BCM2711/BCM2835 ARM ARCHITECTURE),
        linux-pci@vger.kernel.org (open list:PCI NATIVE HOST BRIDGE AND
        ENDPOINT DRIVERS), linux-kernel@vger.kernel.org (open list)
Subject: [PATCH 06/15] PCI: brcmstb: Asserting PERST is different for 7278
Date:   Tue, 19 May 2020 16:34:04 -0400
Message-Id: <20200519203419.12369-7-james.quinlan@broadcom.com>
In-Reply-To: <20200519203419.12369-1-james.quinlan@broadcom.com>
References: <20200519203419.12369-1-james.quinlan@broadcom.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Jim Quinlan <jquinlan@broadcom.com>

The PERST bit was moved to a different register in 7278-type
STB chips.  In addition, the polarity of the bit was also
changed; for other chips writing a 1 specified assert; for
7278-type chips, writing a 0 specifies assert.

Signal-wise, PERST is an asserted-low signal.

Signed-off-by: Jim Quinlan <jquinlan@broadcom.com>
---
 drivers/pci/controller/pcie-brcmstb.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index 39993203b991..2c470104ba38 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -81,6 +81,7 @@
 
 #define PCIE_MISC_PCIE_CTRL				0x4064
 #define  PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK	0x1
+#define PCIE_MISC_PCIE_CTRL_PCIE_PERSTB_MASK		0x4
 
 #define PCIE_MISC_PCIE_STATUS				0x4068
 #define  PCIE_MISC_PCIE_STATUS_PCIE_PORT_MASK		0x80
@@ -679,9 +680,17 @@ static inline void brcm_pcie_perst_set(struct brcm_pcie *pcie, u32 val)
 {
 	u32 tmp;
 
-	tmp = readl(pcie->base + PCIE_RGR1_SW_INIT_1(pcie));
-	u32p_replace_bits(&tmp, val, PCIE_RGR1_SW_INIT_1_PERST_MASK);
-	writel(tmp, pcie->base + PCIE_RGR1_SW_INIT_1(pcie));
+	if (pcie->type == BCM7278) {
+		/* Perst bit has moved and assert value is 0 */
+		tmp = readl(pcie->base + PCIE_MISC_PCIE_CTRL);
+		u32p_replace_bits(&tmp,
+				  !val, PCIE_MISC_PCIE_CTRL_PCIE_PERSTB_MASK);
+		writel(tmp, pcie->base +  PCIE_MISC_PCIE_CTRL);
+	} else {
+		tmp = readl(pcie->base + PCIE_RGR1_SW_INIT_1(pcie));
+		u32p_replace_bits(&tmp, val, PCIE_RGR1_SW_INIT_1_PERST_MASK);
+		writel(tmp, pcie->base + PCIE_RGR1_SW_INIT_1(pcie));
+	}
 }
 
 static inline int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie,
-- 
2.17.1